Here is the design I’m thinking about (I’m going for simplicity) for my single grapevine:
I’m wondering if a horizontal brace bar is necessary for a single grapevine. If it is, I’ll have to go with lumber, because I don’t think metal ones exist. I would have to use a bracket to make it happen (see photo below).
For the posts I’m going with T posts (8 feet long, with 2 of that being in the ground)
I am wondering if holes can be drilled through the T posts, in order to run the catch wire attachment bars through.
I just came back from the home improvement store. T-posts weren’t going to achieve what I was describing above. They don’t have holes and you can’t drill any unless you want to break your drill. I ended up finding something perfect for the job: 8ft perforated angle.
Does anyone know if turnbuckles are a proper substitute for anchor vises? Anchor vises can only be bought online and I need something sooner rather than later, and secondly because I don’t need a pack of 10 like they sell online.
Grape trellises work best if they are in the form of a “T”. I use 8 ft T-Posts and weld a crossbeam at the top. I drill holes in the cross beam and run two wires separated by at least 3 feet horizontally. Good bracing at the end of the row is required. You can use a 45 degree angle brace or can use posts driven into the ground with wire and a turnbuckle to keep it tight. I don’t like using the wire and turnbuckle because it makes mowing difficult. 45 degree angle braces work fairly well because the brace is under the vines which suppress grass growth.
Why use only two wires? The way I have my trellis set up, I can mow under the vines if I choose. When picking grapes, they are at head height which allows me to walk under the vines. Sunlight collection with this type trellis is maximum.
Some international vineyards use up to 6 horizontal wires to increase sunlight capture. Vertical trellis such as the diagram you posted are rarely used. There are too many limitations in terms of production, difficulty pruning, difficulty picking the fruit, etc.
As you note, it is almost impossible to drill holes in T-posts. I found some extra hard drill bits that can do the job. However, I don’t recommend drilling T-posts because bolted on attachments are subject to problems when fruit load is very high. U-bolts are a better alternative. Put one on the T-post and drill holes in the cross beam to fit. Clamp down the U-bolt and it will be as solid as a welded on attachment.
Based on your description, it seems like you have a “top wire cordon” trellis with two foliage support wires that allows the shoots to rest up and over them and then hang down like curtains, if I’m not mistaken. The problem is that my variety of grape has upward growth habit. And from what I’ve researched, we are supposed to be matching the trellis to the growth habit of the grape cultivar. Would it not be awkward for my upright growing grapevinne to be trellised via TWC (top wire cordon)? I have trouble imagining how that would look. Would the shoots bend and break under their own weight as the grow horizontally and refuse to go down? Or would they just extend out over the foliage support wires, bend down due to weight, and curve back up again?
McMaster Carr may have the best selection of assorted hardware online, fwiw. They have a warehouse somewhere in Ohio, and I kid you not, I’ll place an order in the afternoon and sometimes we will have it arrive the next morning, north of Pittsburgh. Their prices are sometimes very low compared to Lowe’s /HD but sometimes much higher depending on the item. We usually get stainless steel hardware cheap so it doesn’t corrode in acid mine water. If you don’t want to worry about rust that might be a good route.
Edit: I have not built one myself yet, but I was thinking about using stainless steel wire rope for a similar project. Susquehanna Wire Rope and Rigging is where we get it normally. I’m not sure if they ship.
I’m using scrap steel salvaged from phone offices I’ve worked in. Sorry, can’t help with things to buy, but if I were purchasing something, I’d find a steel supplier and buy some square steel tubing. The cross beams I use are for muscadines and should be 3.5 feet to 4 feet long. I put up some in years past that were only 3 feet long and always had problems with the vines completely covering the trellis which requires more pruning effort in late winter. The trellises I’ve seen used for bunch grapes had horizontal wires spaced 2 feet apart. I don’t know if this is optimum spacing for the varieties you are growing.
I don’t know why I thought the metal angles I mentioned above would be a good idea. They are a terrible idea. They are easily bendable. I guess I was desperate to put together something with “fishing line and duct tape”, for a lack of better ideas.
So I went searching the internet like a maniac for a solution. I definitely don’t like to use wood posts, so I had to make a metal trellis idea work. As I mentioned above, the problem with T-posts is that there is no hole to run crossbars through (crossbars that you would attach the the foliage catch wires to).
I’m about to share an incredible secret with you guys. Yes, it’s a secret, seeing that no one suggested these ideas. I don’t want to hear “oh yea we already know what that is, blah blah blah”.
You can actually use T-posts as a VSP trellis! They key is these u-bolts with slanted tops. They allow you to attach crossarm bars (which the company also sells, or you can make your own using lumber and drill holes) for the foliage catch wires, and simultaneously face both T-posts in the same direction (which I desire because I want a horizontal brace bar running from the top of one T post the the top of the other T post, using T post brackets, and this will avoid putting brace wires in the ground which you can trip over and can’t mow around).
In other words, they were made for VSP trellis using T posts!
That company is actually a bulk supplier. So I found a website where the home grape grower can actually purchase these tools: orchardvalleysupply.com